With the increasing demand for the size and thickness reduction of the semiconductor device (semiconductor integrated circuit device), a wiring film substrate such as a film made of an insulating resin layer has been used. The use of such a film substrate makes it possible to achieve the reduction in thickness of the semiconductor device.
A manufacturing method of the CSP type semiconductor device having solder bumps in which a wiring film substrate (wiring film) is used is disclosed in the gazette of Japanese Patent Application Laid-Open No. 11-102944.
In this document, the manufacturing method of a semiconductor device is described, which comprises the steps of: (1) temporarily fixing a wiring film on a support plate having an attachable/detachable punching return portion; (2) fixing a semiconductor chip, connecting bonding wires, and forming a resin encapsulation layer; (3) removing the punching return portion and forming solder bumps in a lattice pattern on a rear surface of the wiring film; and (4) dividing the wiring film by cutting the connection portions at the four corners of the cutting lines previously provided along the edges of the resin encapsulation layer. In this manufacturing method of a semiconductor device, the edges of the wiring film are protruded from the outer rim of the resin encapsulation layer serving as an encapsulation.